Expansion size envelope



Jan. 26, 1965 F. J. MEYER 3,167,242

EXPANSION SIZE ENVELOPE Filed Jan. 3]., 1963 2 Sheets-Sheet 1 H1 ll 3 13 16 L15 Jan. 26, 1965 F. J. MEYER 3,157,242

EXPANSION SIZE ENVELOPE Filed Jan. 51, 1963 2 Sheets-Sheet 2 3,167 ,242 EXPANSIGN SIZE ENVELGPE Frank Joseph Meyer, Smokerise, Kinnelon, N.J., assignor to Kimherly-Ciarlr Corporation, Neeuah, Wis, a cerporation of Delaware Filed Jan. 31, 1963, Ser. No. 255,320 3 Claims. ((31. 229-68) panded.

A primary object of the invention is to provide an improved one-piece expansion envelope of simplified construction.

Another object is to provide an expansion type envelope of considerably less bulk in which only the bottom flap requires multiple folding, and wherein the need for pleats in the side flaps is eliminated.

It is a further object of the invention to provide a flat expansion type envelope in which the bottom flap is folded and secured to the side flaps in a manner to form an unbroken bottom panel which when in fully opened condition is free of tucks, glue laps or extraneous folds.

Other objects and advantages of the invention will become apparent to persons skilled in the art, upon examination of the accompanying drawings and description, without departure from the concepts herein taughts as defined in the appended claims.

In the drawings, in which like parts are identified by the same reference numerals,

FIGURE 1 is a plan view of a one-piece blank from which a preferred form of the envelope may be made.

FIGURE 2 is a plan view of the back side of an evelope assembled from the blank of FIG. 1.

FIGURE 3 is an enlarged partial section through line 3-3 of FIG. 2 showing the disposition of the various planar portions of the expandable bottom section.

FIGURE 4 is an enlarged fragmentary view in perspective taken through the front panel of the assembled envelope showing a bottom corner in fully opened condition.

Expansion type envelopes having infolded side pleats and outfolded bottom pleats are generally well-known in the industry. Such envelopes are largely handmade and comparatively expensive because of the labor costs involved. While some types of expansion envelopes have recently been developed which are adapted for fabrication on automatic machines, the infolded side and outfolded bottom members require multiple compound folds which not only increase the bulk at the corners of the folded envelope but complicate handling on such machines.

The expansion envelope of this invention overcomes some of the above disadvantage by eliminating side pleats and simplifying the structure of the bottom panel. The improved features of the preferred envelope construction may be readily understood by reference to the drawings and accompanying description.

The one-piece blank of FIG. 1, from which the envelope is formed, may be suitably die-cut from paper or similar flexible sheet stock, and consists of a main body portion 1, an upper flap 2 connected to the main body along fold line 4, side flaps 5 and 6 connected to the main body along lateral fold lines 7 and 8 respectively, and a lower flap designated generally at 9 connected to the main body and juxtaposed portions of the side flaps along transverse fold line 10.

In constructing the envelope from the blank, a suitable f United States Patent 0 adhesive is first applied to flap 9 in selected areas 11 and 12, with adjacent areas He: and 12a remaining free of adhesive. Flap 9 is then first folded inwardly along transverse fold line 10 to adhesively attach areas 11 and 12 to their respective side flaps. Flap 9 is then folded outwardly along fold transverse line 13 to bring sections 19 and 20 thereof into overlying relationship. At this stage, side flap 6 is folded inwardly along lateral fold line 8, and side flap 5 is folded inwardly along lateral fold line 7 after a suitable adhesive is applied to area 14 for adhesive attachment of the folded and overlapped side flaps to each other. Lower flap 9 then has a suitable adhesive applied to area 15, and that section of flap 9 is subsequently folded inwardly along transverse fold line 16 for adhesive attachment to the previously folded and overlapped side flaps to complete assembly of the envelope. A plan view of the rear side of the assembled envelope is shown in FIG. 2.

It is understood that upper flap 2 may have a suitable adhesive applied thereto for sealing purposes, or the envelope may have a metal clasp, string and button, or other type closure incorporated therein.

When lower flap 9 is folded and portions 11 and 12 glued only to the side flaps as described, an expandable pleat or gusset is formed in the bottom of the assembled envelope which readily expandsto form a flat floor of substantially rectangular configuration when bulky materials are inserted in the envelope. Because the expandable bottom panel is folded inwardly, as shown, it does not add to the length of the envelope when foldled flat for storage, another advantage over envelopes with the older bag type bottom.

The partial section, shown in enlarged detail in FIG. 3, illustrates in more detail the assembled relationship of the various planes of sheet material in one corner of the expandable bottom portion of the envelope. Sealing flap 15 is adhesively attached to side flap 5 by a suitable adhesive 18. The portion 12 of the bottom flap which extends beyond fold line 7 is adhesively attached to side flap 5 in their area of common engagement by adhesive 17. Portion 12a of the bottom flap is free of adhesive and unattached. Fold line 13 of the bottom flap extends transversely across the entire bottom of the envelope and is also free of adhesive, as is the main body portion 1.

FIG. 4 shows in detail the disposition of the various sections of the bottom panel when the envelope is expanded to a fully opened condition. Sections 19 and 20 move downwardly and out from their folded position to flatten fold line 13 and provide an essentially planar bottom of substantially rectangular configuration. Insertion of materials into the envelope and the subsequent flattening out of fold line 13 causes the lateral edges of side flap 6 and the adjacent main body portion 1 of the envelope to distend outwardly from their juxtaposed position at fold line 8 forming well-defined somewhat rounded corners 21 and 22, and forming side walls of a similar width as the planar bottom panel. The substantially flat rectangular bottom formed by sections 19 and 29 is completely free of tucks, glue laps, or extraneous folds. The simple adhesive attachment of flap section 11 to side flap 6 (and corresponding attachment of flap section 12 to side flap 5, not shown since it is a mirror image of FIG. 4) completely seals the bottom of the envelope without requiring supplementary tucking or folding.

If desired, the main body portion 1 or face of the envelope may be provided with a die-cut window, either patched or open, for addressing or other purposes.

While the above description is directed primarily to an envelope made from a blank of unitary construction, it can readily be seen that the absence of tucks or glue laps for incorporation of a transparent material as, the entire 7' ledges of said body portion bottom member if a display typepackage with a bottom Window is desired. 7

' The construction described herein is readily adaptable for use with conventional papers, lightweight paperboard,

or similar flexible sheet stock. t a

As previously mentioned, the simplified structure of the envelope of this invention makes it particularly adapt-t able to fabrication on high-speed automatic 1 machines without the necessityfor major modification in the equip Supplementary trade finishing to incorporate such,

1. An. expansion type envelope comprising a main body portion and flaps at the upper, lower and sideedges thereof, said flaps adapted for folding inwardly onrsaid body, the upper and side flaps being of substantially the same length as said body at the respective fold lines, the

t 4. r V V I partly alongside and attached 'to each of the side flaps and an outer portion of substantially the same width as said ,body portion, said lower flap being transverselytrnultifolded first inwardly along the line where it joins said body portion, then outwardly medially of said inner portion and then inwardly again on a line where said inner and outer'portions join to partially overlie said body portion and said side flaps, the transversely folded portions. of said lower flap in juxtaposed contact with said sideflaps being adhered thereto only in said area of contact,-said side flapsbeing laterally folded inwardly in overlapping engagement to overlie said body portion and the outwardly transverselytolded portion of said lower; flap, the second inwardly folded portionof said lower'flap overlying and being adhered to the folded sidefla'ps} f 7 a 1 3. An expansion type envelope havinga rnultifolded bottom flap and unpleated sides, said envelope being lower flap having an inner portion of greater length than said body at'the common fold line therewith and extend-v 1 ing'along both side flapsbeyond the lateral fold lines of saidside flaps and an outer portion of substantially the same lengthassaid body, said. lower flap. being transversely folded first inwardly on said body' and on. said made from a die-cut blank comprising a central panel, 'upper,v lower and sidefia'ps, said, upper andside flaps being coextensive with the'r'espective lateraledges of, said centraltpane'l, said lower flap, having a wider inner portion extending transversely. beyond the lateral edges of transversely pleated and folded inwardly medially of said wider inner portionato partially, overlie the central panel hered to saidside flaps only in the area of common con-' tact, said side flaps and said attached portions of said;-

extending outer portion of said lower-flap being folded tirrv wardly over said folded side flaps and adhered thereto. I

v 2. An expansiontype envelope -madefrom a singlet blank comprising a central body portion, upper, lower, and side flaps, said upper and side flaps beingcoextensive with thelateral edges'of saidrbody portion, said lower flap having an inner portion extendingbeyond the side 4 and a portion 'of'the sideflaps, said transversely folded 7 lower fiap'being adhesively'attached to said side flaps only in the area, of common contact with, said side flaps, said side flaps and attached portiontof said lower flap being laterally; folded inwardly over said central panel and over the inner pleat offs aid lower flap and adhered together in overlapping engagement, the outer narrower portion of Swortfiguer Aug. 15, 1916 Hiersteiner Jan. 15, 1963 

1. AN EXPANSION TYPE ENVELOPE COMPRISING A MAIN BODY PORTION AND FLAPS AT THE UPPER, LOWER AND SIDE EDGES THEREOF, SAID FLAPS ADAPTED FOR FOLDING INWARDLY ON SAID BODY, THE UPPER AND SIDE FLAPS BEING OF SUBSTANTIALLY THE SAME LENGTH AS SAID BODY AT THE RESPECTIVE FOLD LINES, THE LOWER FLAP HAVING AN INNER PORTION OF GREATER LENGTH THAN SAID BODY AT THE COMMON FOLD LINE THEREWITH AND EXTENDING ALONG BOTH SIDE FLAPS BEYOND THE LATERAL FOLD LINES OF SAID SIDE FLAPS AND AN OUTER PORTION OF SUBSTANTIALLY THE SAME LENGTH AS SAID BODY, SAID LOWER FLAP BEING TRANSVERSELY FOLDED FIRST INWARDLY ON SAID BODY AND ON SAID SIDE FLAPS AND THEN FOLDED OUTWARDLY MEDIALLY OF SAID INNER PORTION WITH SAID OUTER PORTION EXTENDING BEYOND SAID FIRST INWARD FOLD, THE INWARDLY FOLDED PORTIONS OF SAID LOWER FLAP WHICH OVERLIE SAID SIDE FLAPS BEING ADHERED TO SAID SIDE FLAPS ONLY IN THE AREA OF COMMON CONTACT, SAID SIDE FLAPS AND SAID ATTACHED PORTIONS OF SAID LOWER FLAP BEING INWARDLY FOLDED OVER SAID BODY AND OVER THE FOLDED INNER PORTION OF SAID LOWER FLAP, SAID SIDE FLAP BEING ADHERED IN OVERLAPPING ENGAGEMENT, THE OUTWARDLY EXTENDING OUTER PORTION OF SAID LOWER FLAP BEING FOLDED INWARDLY OVER SAID FOLDED SIDE FLAPS AND ADHERED THERETO. 